package cn.co.Servlet;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.net.URLDecoder;
import java.net.URLEncoder;
import java.text.SimpleDateFormat;
import java.util.Date;

@WebServlet(name = "LastAccessServlet",urlPatterns = "/LastAccessServlet")
public class LastAccessServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException,IOException {
        doPost(request,response);
    }
    public void doPost(HttpServletRequest request,HttpServletResponse response)throws ServletException,IOException{
        //指定服务器输出内容的编码方式UTF-8，防止发生乱码
        response.setContentType("text/html;charset=utf-8");
        //获取所有cookie
        Cookie[] cookies=request.getCookies();
        //定义flag的boolean变量，用于判断cookies是否为空
        boolean flag=false;
        //遍历cookie数组
        if(cookies.length >0&&cookies!=null){
            for(Cookie cookie:cookies) {
                //获取cookie的名称
                String name=cookie.getName();
                //判断名称是否是lastTime
                if("lastTime".equals(name)){
                    //有该cookie不是第一次访问
                    flag=true;
                    //响应数据
                    //获取cookie的value时间
                    String value=cookie.getValue();
                    System.out.println("解码前："+value);
                    //URL解码
                    value= URLDecoder.decode(value, "utf-8");
                    System.out.println("解码后："+value);
                    response.getWriter().write("欢迎回来，您上次访问时间为:"+value);
                    //设置cookie的value
                    //获取当前时间的字符串，重新设置cookie的值，重新发送cookie
                    Date date=new Date();
                    SimpleDateFormat timesdf=new SimpleDateFormat("yyyy年MM月dd日 HH:mm:ss");
                    String str_time=timesdf.format(date);
                    System.out.println("编码前："+str_time);
                    //URL编码
                    str_time=URLEncoder.encode(str_time, "utf-8");
                    System.out.println("编码后："+str_time);
                    cookie.setValue(str_time);
                    //设置cookie存活时间
                    cookie.setMaxAge(60*60*24*30);	//一个月
                    //加入当前cookie请求时间
                    response.addCookie(cookie);
                    break;
                }
            }
            //如果cookies中没有时间，也就是没有访问过
            if(cookies==null || cookies.length==0 || flag==false){
                //设置cookie的value
                //获取当前时间的字符串，重新设置cookie的值，重新发送cookie
                Date date=new Date();
                SimpleDateFormat sdf=new SimpleDateFormat("yyyy年MM月dd日 HH:mm:ss");
                String str_date=sdf.format(date);
                System.out.println("编码前："+str_date);
                //URL编码
                str_date= URLEncoder.encode(str_date,"utf-8");
                System.out.println("编码后："+str_date);
                Cookie cookie=new Cookie("lastTime",str_date);
                //设置cookie存活时间
                cookie.setMaxAge(60*60*24*30);//一个月
                response.addCookie(cookie);
                response.getWriter().write("您好，欢迎您首次访问");
            }
    }
}
}
